Novel Ironmaking Technol - Peru 2012

7/27/2019 Novel Ironmaking Technol - Peru 2012

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Novel Flash Ironmaking Technologywith Greatly Reduced Energy

Consumption and CO2 Emissions

Hong Yong Sohn

Department of Metal lurgical Engineer ing

University of Utah


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University of Utah Teamon AISI Project

Hong Yong SohnPI & ProfessorMike MoatsAssistant Professor

Moo Eob ChoiProject Manager & Research Assistant ProfessorMiguel OlivasSenior Grad. Assistant

Silvia PerezGraduate Assistant

Yousef MohassabSenior Grad. AssistantTyler BronsonGraduate Assistant

Z. Chris YuanGraduate Assistant

Colton HenlineUndergraduate Assistant

Udo FischerUndergraduate Assistant

ConsultantsY. G. Kim (> 15 yrs. in control); A. Ullah (> 30 yrs. in DRI)

Graduated: Max Yao ZhangM.S. 2008; M. E. ChoiPh.D. 2010;

Haruka KimuraM.S. 2010; Haitao WangPh.D. 2011;

Yousef MohassabM.S. 2011; Sara Liu - M.S. 2011

Hang Goo KimPast Project Mgr. & Res. Assoc. Prof. 08-11;

now Director, POSCO M-Tech


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Partner Companies

AK Steel

ArcelorMittal

Gallatin Steel

Heckett MultiServNucor

Praxair

Severstal North America

SSABSteel Dynamics

Ternium

Timken

US Steel


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Overall Objective

Develop a new ironmaking process

--- Significant reduction in CO2 generation

and energy consumption

Based on:

Hydrogen (Natural Gas, Coal)

Direct use ofconcentrate

Without coke

Without pelletization/sintering


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Background

Blast Furnace

Merits: Well developed, Large size,

Economical

Issues:

- RequiresCokeand Iron OrePellets- LargeCO2 Emission

- LargeEnergy Consumption


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Main Motivation(Reasons for expected success)

Needs for CO2 reduction

Developments toward H2

economy

Availability ofless C-intensivefuels/

reductants

Availability offine (~30 m) iron oreconcentrates


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Outokumpu Copper Flash Furnace


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Reduction offine iron ore

particles in suspension with H2 as

reductant

Possible use ofnatural gas or coal

Target: replace BF/BOF route

Proposed Process Concept


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Advantages of Flash Smelting

relevant to ironmaking

-

High Reaction rates:Very small particles dispersed in gas

Easy process Control:Continuous operation


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Major Differences

Exothermic vs Endothermic

Irreversible vs Equilibrium-Limited

More vs Less Corrosive

Toxic vs Combustible Atmosphere

Different issues to address/resolve

Need for development work


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1.6

0.04

1.021.08

Avg. Blast Furnace Flash Ironmaking(Hydrogen)

Flash Ironmaking(Natural Gas

w/o Reformer)

Flash Ironmaking(Natural Gas

w/ Reformer)

CO2(tons/tonm

olteniron

CO2 Emission(tons per ton iron)

Carbon dioxide emission from ore/coke preparation is not included

% of BF = 2.5 % (H2); 64 % (Natural Gas w/o Reformer)


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12.7

5.7

8.9

12.9

Avg. Blast Furnace Flash Ironmaking(Hydrogen)

Flash Ironmaking(Natural Gas,

w/o Reformer)

Flash Ironmaking(Natural Gas,

w/ Reformer)

En

ergyRequirement(G

J/ton

molteniron)

Energy Requirement(GJ per metric ton molten iron)

Pelletizing = 3, Sintering = 0.7, Cokemaking = 2

% of BF = 45 % (H2); 70 % (Natural Gas w/o Reformer)


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Technical Issues

Rate ofH2 reduction

Heat supply Hydrogen utilization

Equilibrium limitation


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Rateof H2 reduction


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Drop-Tube Reactor System


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Drop-Tube Reactor System


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Reduction at 1000oC20 - 32 m (- 500 + 635 mesh)

2-second reduction

(32% metallization)

30-second reduction

(100% metallization)


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2-second reduction

(50% metallization)10-second reduction

(100% metallization)

Reduction at 1100oC


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100% reduction,

2.7 seconds

Reduction at 1350oC


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Rate Determination

Rate is fast enough for a suspension

process in H2 above 1200C.


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Definition of % excess H2

Equilibrium gas composition vs. temperature


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Rate is fast enough for a suspension

process in H2 above 1200C.

Effect of Temperature


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Modified Flash Reactor

Powder feeder

Preheater

Collection ChamberOffgas Scrubber


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OreFeeder

H2 H2

O2O2

Heating

Element(SiC)

Heating

Element

(SiC or

Superkantal)

Filled with

Ceramic

Balls

0.25 in0.375 in

No Welding

5 in

3 in

1 in

0.5 in

0.25 in

0.375 (3/8) in

0.5 in2 in

1in

7.625 in

0.5 in

1.5 in2in

10 in

2.75 in OD

2.5 in ID

0.25 in ID

1 in

0.125 in

0.5 in

0.25 in

0.25 in

0.375 in Flange1

Flange2


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For higher reduction and feeding rate, longer

residence time or higher T needed.

1150oC

Rate Measurements


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Heat Supply and Burner Design

Process is Endothermic.

Equilibrium LimitationMust generate sufficiently reducing hot gas

Safety in Burning Hydrogen


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Computational Fluid Dynamic

Modeling

CFD Modeling will be very helpful in

Reactor design and Analyzing test data:

Bench and Pilot

Will be even more helpful in

Selecting reactor type:

Pilot and Commercial


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Factors to Quantify leading toModeling


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Flame TemperatureBench Scale(Values in Kelvin)


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Computational Fluid Dynamics Modeling of

Flash Smelting Process

x

y

z

OXYGEN-ENRICHED AIR

MOLTEN BATH

SURFACE

TO UPTAKE

SHAFT

O 2

SO 2

I

REACTION SHAFT

COPPER MATTE

PARTICLES

PARTICLE CLOUDS

x

y

z

OXYGEN-ENRICHED AIROXYGEN-ENRICHED AIR

MOLTEN BATH

SURFACE

TO UPTAKE

SHAFT

TO UPTAKE

SHAFT

O 2

SO 2

I

REACTION SHAFTREACTION SHAFT

COPPER MATTE

PARTICLES

COPPER MATTE

PARTICLES

PARTICLE CLOUDSPARTICLE CLOUDS


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Gas temperature in an industrial

flash furnace

(a) single axial entry burner

(b) 85-distributor cone burner


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Drastic reduction in CO2 emission.

Energy savings up to 45% of BF process.

Eliminating the use ofcoke and

pelletization/sintering, with associated

generation ofpollutants.

H2reduction ofconcentrate: 90-99%

reduction in1-7 seconds at 1200-1400oC;

sufficiently fastfor a suspension process.

Summary of Results

AISI CO2 Breakthrough Program


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What Now and Next

Phase

I

(Completed)

II III

(Future)(Paused) (New)

Scale Lab Bench Large Bench Industrial Pilot

Start(Duration)

2005(2.5 years)

2008(4 years)

2012(3 years)

2016(3.5 years)

Max. RateofProdn

-24

(tons/year)36

(tons/year)50,000

(tons/year)

Location Univ. of Utah Univ. of Utah Univ. of Utah Industrial Site

MainOutput

Verification of

ProcessFeasibility

Engineering

Datafor Scale-up

Engineering

Datafor Scale-up

Preparation forCommercialization

ResearchBudget

~ US$ 0.5 MM ~ US$ 2.5 MM US$ 8.9 MM ~ US$ 40-60 MM


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Process Simulation- Sample Flowsheet

Material and energy flows for the commercial-scale (1 MM tons/year)

reformerless ironmaking process


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Economic Feasibility Analysis

* NPV: Net Present Value

** SMR: Steam-Methane Reforming

H2 price: $2.5/kg, Natural gas price: $6/million Btu

Iron price: $445/ton

NPV estimation based on 15 year operation

H2-based

1-step

process

H2-based

2-step

process

1-step process:

H2 production

from SMR**

1-step process:

reformerless

natural gas

- 475 - 530 103 411

Pre-Tax NPV* comparison (million $)1 million tons per year

P Si l ti


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- Economic feasibility promising with natural gas

(even without C penalty)

- More profitable at higher CO2 emissions credits

- Ironmaking with purchased H2 not economical currently

Need C credit or cheaper H2

- Capital cost lower with purchased H2 than reformerlessuse of natural gas

- Drastic reduction of H2 requirement by preheating H2

Process Simulation-Results


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Slides for possible discussion

CO Emissions from U S Steel IndustryCO Emissions from U S Steel Industry


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Adapted from Report DOE/EIA-0573(2005), Special Topic: Energy-Related Carbon Dioxide

Emissions in U.S. Manufacturing, 2006.

100126.0Total

0.91.2Other

52.966.7Coal

0.91.1Petroleum

17.522.0Natural gas

27.835.0Net electricity

%2002Source

(Million Metric Tons)

CO2 Emissions from U.S. Steel Industry

Adapted from Report DOE/EIA-0573(2005), Special Topic: Energy-Related Carbon Dioxide

Emissions in U.S. Manufacturing, 2006.

100126.0Total

0.91.2Other

52.966.7Coal

0.91.1Petroleum

17.522.0Natural gas

27.835.0Net electricity

%2002Source

(Million Metric Tons)

CO2 Emissions from U.S. Steel Industry


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Rate ofH2Reduction Extrapolation of previous rate data:

- Deemed too slow for suspension process

Careful examination of data and otherfactors showed possibility of higher rate.

- Factors: Low activation energy ~ 3 kcal

indicates diffusional effects- Assumption ofround geometry

- Basis for current project


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Particle Geometry

d1

dr

Novel Ironmaking Technol - Peru 2012

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